Added skeleton for inline asm multiple alternative constraint support.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113766 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index e657445..1e77a66 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -5008,7 +5008,7 @@
/// contains the set of register corresponding to the operand.
RegsForValue AssignedRegs;
- explicit SDISelAsmOperandInfo(const InlineAsm::ConstraintInfo &info)
+ explicit SDISelAsmOperandInfo(const TargetLowering::AsmOperandInfo &info)
: TargetLowering::AsmOperandInfo(info), CallOperand(0,0) {
}
@@ -5069,7 +5069,7 @@
return TLI.getValueType(OpTy, true);
}
-
+
private:
/// MarkRegAndAliases - Mark the specified register and all aliases in the
/// specified set.
@@ -5324,28 +5324,15 @@
std::set<unsigned> OutputRegs, InputRegs;
- // Do a prepass over the constraints, canonicalizing them, and building up the
- // ConstraintOperands list.
- std::vector<InlineAsm::ConstraintInfo>
- ConstraintInfos = IA->ParseConstraints();
-
- bool hasMemory = hasInlineAsmMemConstraint(ConstraintInfos, TLI);
-
- SDValue Chain, Flag;
-
- // We won't need to flush pending loads if this asm doesn't touch
- // memory and is nonvolatile.
- if (hasMemory || IA->hasSideEffects())
- Chain = getRoot();
- else
- Chain = DAG.getRoot();
-
+ std::vector<TargetLowering::AsmOperandInfo> TargetConstraints = TLI.ParseConstraints(CS);
+ bool hasMemory = false;
+
unsigned ArgNo = 0; // ArgNo - The argument of the CallInst.
unsigned ResNo = 0; // ResNo - The result number of the next output.
- for (unsigned i = 0, e = ConstraintInfos.size(); i != e; ++i) {
- ConstraintOperands.push_back(SDISelAsmOperandInfo(ConstraintInfos[i]));
+ for (unsigned i = 0, e = TargetConstraints.size(); i != e; ++i) {
+ ConstraintOperands.push_back(SDISelAsmOperandInfo(TargetConstraints[i]));
SDISelAsmOperandInfo &OpInfo = ConstraintOperands.back();
-
+
EVT OpVT = MVT::Other;
// Compute the value type for each operand.
@@ -5393,33 +5380,35 @@
}
OpInfo.ConstraintVT = OpVT;
+
+ // Indirect operand accesses access memory.
+ if (OpInfo.isIndirect)
+ hasMemory = true;
+ else {
+ for (unsigned j = 0, ee = OpInfo.Codes.size(); j != ee; ++j) {
+ TargetLowering::ConstraintType CType = TLI.getConstraintType(OpInfo.Codes[j]);
+ if (CType == TargetLowering::C_Memory) {
+ hasMemory = true;
+ break;
+ }
+ }
+ }
}
+ SDValue Chain, Flag;
+
+ // We won't need to flush pending loads if this asm doesn't touch
+ // memory and is nonvolatile.
+ if (hasMemory || IA->hasSideEffects())
+ Chain = getRoot();
+ else
+ Chain = DAG.getRoot();
+
// Second pass over the constraints: compute which constraint option to use
// and assign registers to constraints that want a specific physreg.
- for (unsigned i = 0, e = ConstraintInfos.size(); i != e; ++i) {
+ for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i];
- // If this is an output operand with a matching input operand, look up the
- // matching input. If their types mismatch, e.g. one is an integer, the
- // other is floating point, or their sizes are different, flag it as an
- // error.
- if (OpInfo.hasMatchingInput()) {
- SDISelAsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
-
- if (OpInfo.ConstraintVT != Input.ConstraintVT) {
- if ((OpInfo.ConstraintVT.isInteger() !=
- Input.ConstraintVT.isInteger()) ||
- (OpInfo.ConstraintVT.getSizeInBits() !=
- Input.ConstraintVT.getSizeInBits())) {
- report_fatal_error("Unsupported asm: input constraint"
- " with a matching output constraint of"
- " incompatible type!");
- }
- Input.ConstraintVT = OpInfo.ConstraintVT;
- }
- }
-
// Compute the constraint code and ConstraintType to use.
TLI.ComputeConstraintToUse(OpInfo, OpInfo.CallOperand, &DAG);
@@ -5427,7 +5416,7 @@
// need to to provide an address for the memory input.
if (OpInfo.ConstraintType == TargetLowering::C_Memory &&
!OpInfo.isIndirect) {
- assert(OpInfo.Type == InlineAsm::isInput &&
+ assert((OpInfo.isMultipleAlternative || (OpInfo.Type == InlineAsm::isInput)) &&
"Can only indirectify direct input operands!");
// Memory operands really want the address of the value. If we don't have
@@ -5469,8 +5458,6 @@
GetRegistersForValue(OpInfo, OutputRegs, InputRegs);
}
- ConstraintInfos.clear();
-
// Second pass - Loop over all of the operands, assigning virtual or physregs
// to register class operands.
for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) {
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index b74f600..419784d 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -2654,6 +2654,156 @@
return atoi(ConstraintCode.c_str());
}
+
+/// ParseConstraints - Split up the constraint string from the inline
+/// assembly value into the specific constraints and their prefixes,
+/// and also tie in the associated operand values.
+/// If this returns an empty vector, and if the constraint string itself
+/// isn't empty, there was an error parsing.
+std::vector<TargetLowering::AsmOperandInfo> TargetLowering::ParseConstraints(
+ ImmutableCallSite CS) const {
+ /// ConstraintOperands - Information about all of the constraints.
+ std::vector<AsmOperandInfo> ConstraintOperands;
+ const InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue());
+
+ // Do a prepass over the constraints, canonicalizing them, and building up the
+ // ConstraintOperands list.
+ std::vector<InlineAsm::ConstraintInfo>
+ ConstraintInfos = IA->ParseConstraints();
+
+ unsigned ArgNo = 0; // ArgNo - The argument of the CallInst.
+ unsigned ResNo = 0; // ResNo - The result number of the next output.
+
+ for (unsigned i = 0, e = ConstraintInfos.size(); i != e; ++i) {
+ ConstraintOperands.push_back(AsmOperandInfo(ConstraintInfos[i]));
+ AsmOperandInfo &OpInfo = ConstraintOperands.back();
+
+ EVT OpVT = MVT::Other;
+
+ // Compute the value type for each operand.
+ switch (OpInfo.Type) {
+ case InlineAsm::isOutput:
+ // Indirect outputs just consume an argument.
+ if (OpInfo.isIndirect) {
+ OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
+ break;
+ }
+
+ // The return value of the call is this value. As such, there is no
+ // corresponding argument.
+ assert(!CS.getType()->isVoidTy() &&
+ "Bad inline asm!");
+ if (const StructType *STy = dyn_cast<StructType>(CS.getType())) {
+ OpVT = getValueType(STy->getElementType(ResNo));
+ } else {
+ assert(ResNo == 0 && "Asm only has one result!");
+ OpVT = getValueType(CS.getType());
+ }
+ ++ResNo;
+ break;
+ case InlineAsm::isInput:
+ OpInfo.CallOperandVal = const_cast<Value *>(CS.getArgument(ArgNo++));
+ break;
+ case InlineAsm::isClobber:
+ // Nothing to do.
+ break;
+ }
+ }
+
+ // If we have multiple alternative constraints, select the best alternative.
+ if (ConstraintInfos.size()) {
+ unsigned maCount = ConstraintInfos[0].multipleAlternatives.size();
+ if (maCount) {
+ unsigned bestMAIndex = 0;
+ int bestWeight = -1;
+ // weight: -1 = invalid match, and 0 = so-so match to 5 = good match.
+ int weight = -1;
+ unsigned maIndex;
+ // Compute the sums of the weights for each alternative, keeping track
+ // of the best (highest weight) one so far.
+ for (maIndex = 0; maIndex < maCount; ++maIndex) {
+ int weightSum = 0;
+ for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
+ cIndex != eIndex; ++cIndex) {
+ AsmOperandInfo& OpInfo = ConstraintOperands[cIndex];
+ if (OpInfo.Type == InlineAsm::isClobber)
+ continue;
+ assert((OpInfo.multipleAlternatives.size() == maCount)
+ && "Constraint has inconsistent multiple alternative count.");
+
+ // If this is an output operand with a matching input operand, look up the
+ // matching input. If their types mismatch, e.g. one is an integer, the
+ // other is floating point, or their sizes are different, flag it as an
+ // maCantMatch.
+ if (OpInfo.hasMatchingInput()) {
+ AsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
+
+ if (OpInfo.ConstraintVT != Input.ConstraintVT) {
+ if ((OpInfo.ConstraintVT.isInteger() !=
+ Input.ConstraintVT.isInteger()) ||
+ (OpInfo.ConstraintVT.getSizeInBits() !=
+ Input.ConstraintVT.getSizeInBits())) {
+ weightSum = -1; // Can't match.
+ break;
+ }
+ Input.ConstraintVT = OpInfo.ConstraintVT;
+ }
+ }
+
+ weight = getMultipleConstraintMatchWeight(OpInfo, maIndex);
+ if (weight == -1) {
+ weightSum = -1;
+ break;
+ }
+ weightSum += weight;
+ }
+ // Update best.
+ if (weightSum > bestWeight) {
+ bestWeight = weightSum;
+ bestMAIndex = maIndex;
+ }
+ }
+
+ // Now select chosen alternative in each constraint.
+ for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
+ cIndex != eIndex; ++cIndex) {
+ AsmOperandInfo& cInfo = ConstraintOperands[cIndex];
+ if (cInfo.Type == InlineAsm::isClobber)
+ continue;
+ cInfo.selectAlternative(bestMAIndex);
+ }
+ }
+ }
+
+ // Check and hook up tied operands, choose constraint code to use.
+ for (unsigned cIndex = 0, eIndex = ConstraintOperands.size();
+ cIndex != eIndex; ++cIndex) {
+ AsmOperandInfo& OpInfo = ConstraintOperands[cIndex];
+
+ // If this is an output operand with a matching input operand, look up the
+ // matching input. If their types mismatch, e.g. one is an integer, the
+ // other is floating point, or their sizes are different, flag it as an
+ // error.
+ if (OpInfo.hasMatchingInput()) {
+ AsmOperandInfo &Input = ConstraintOperands[OpInfo.MatchingInput];
+
+ if (OpInfo.ConstraintVT != Input.ConstraintVT) {
+ if ((OpInfo.ConstraintVT.isInteger() !=
+ Input.ConstraintVT.isInteger()) ||
+ (OpInfo.ConstraintVT.getSizeInBits() !=
+ Input.ConstraintVT.getSizeInBits())) {
+ report_fatal_error("Unsupported asm: input constraint"
+ " with a matching output constraint of"
+ " incompatible type!");
+ }
+ Input.ConstraintVT = OpInfo.ConstraintVT;
+ }
+ }
+ }
+
+ return ConstraintOperands;
+}
+
/// getConstraintGenerality - Return an integer indicating how general CT
/// is.
@@ -2672,6 +2822,76 @@
}
}
+/// Examine constraint type and operand type and determine a weight value,
+/// where: -1 = invalid match, and 0 = so-so match to 3 = good match.
+/// This object must already have been set up with the operand type
+/// and the current alternative constraint selected.
+int TargetLowering::getMultipleConstraintMatchWeight(
+ AsmOperandInfo &info, int maIndex) const {
+ std::vector<std::string> &rCodes = info.multipleAlternatives[maIndex].Codes;
+ int matchingInput = info.multipleAlternatives[maIndex].MatchingInput;
+ TargetLowering::ConstraintType BestType = TargetLowering::C_Unknown;
+ int BestWeight = -1;
+
+ // Loop over the options, keeping track of the most general one.
+ for (unsigned i = 0, e = rCodes.size(); i != e; ++i) {
+ int weight = getSingleConstraintMatchWeight(info, rCodes[i].c_str());
+ if (weight > BestWeight)
+ BestWeight = weight;
+ }
+
+ return BestWeight;
+}
+
+/// Examine constraint type and operand type and determine a weight value,
+/// where: -1 = invalid match, and 0 = so-so match to 3 = good match.
+/// This object must already have been set up with the operand type
+/// and the current alternative constraint selected.
+int TargetLowering::getSingleConstraintMatchWeight(
+ AsmOperandInfo &info, const char *constraint) const {
+ int weight = -1;
+ Value *CallOperandVal = info.CallOperandVal;
+ // If we don't have a value, we can't do a match,
+ // but allow it at the lowest weight.
+ if (CallOperandVal == NULL)
+ return 0;
+ // Look at the constraint type.
+ switch (*constraint) {
+ case 'i': // immediate integer.
+ case 'n': // immediate integer with a known value.
+ weight = 0;
+ if (info.CallOperandVal) {
+ if (isa<ConstantInt>(info.CallOperandVal))
+ weight = 3;
+ else
+ weight = -1;
+ }
+ break;
+ case 's': // non-explicit intregal immediate.
+ weight = 0;
+ if (info.CallOperandVal) {
+ if (isa<GlobalValue>(info.CallOperandVal))
+ weight = 3;
+ else
+ weight = -1;
+ }
+ break;
+ case 'm': // memory operand.
+ case 'o': // offsettable memory operand
+ case 'V': // non-offsettable memory operand
+ weight = 2;
+ break;
+ case 'g': // general register, memory operand or immediate integer.
+ case 'X': // any operand.
+ weight = 1;
+ break;
+ default:
+ weight = 0;
+ break;
+ }
+ return weight;
+}
+
/// ChooseConstraint - If there are multiple different constraints that we
/// could pick for this operand (e.g. "imr") try to pick the 'best' one.
/// This is somewhat tricky: constraints fall into four classes: